Dental implants, which are referred to as artificial teeth or third teeth, are a dental treatment method for restoring a function of a natural tooth by implanting a bio-adaptive implant main body into a portion having tooth deficiency or a jawbone where a tooth is removed.
An implant generally includes a fixture that becomes an artificial tooth root by being implanted in an alveolar bone, an abutment for an implant that is an abutment post by being screw-coupled to an upper end portion of the fixture, and a crown that is a prosthesis having a tooth shape and is coupled to an upper end portion of the abutment.
An example of a dental implant fixture 1 according to a related art is illustrated in FIG. 7. The dental implant fixture 1 may include a main body 2 that is a cylindrical screw portion vertically extending long and at least a part of the main body 2 is implanted in the alveolar bone, a head part 3 coupled to an upper end portion of the main body 2, a first screw hole 4 that is hexagonal and in an upper surface of the head part 3, and a second screw hole 5 on a bottom surface of the first screw hole 4, to which the abutment for an implant may be screw-coupled.
In order to implant the dental implant fixture 1, as illustrated in FIG. 1, a treatment of forming an implant hole H in an alveolar bone B using a dental drill D is needed. Fenestration is performed as illustrated in FIG. 2 so as not to damage a dental nerve N inside the alveolar bone B or a cortical bone S that is an envelope of the alveolar bone B. Since a cancellous bone C inside the alveolar bone B characteristically has a relatively large supply of blood and is soft, the cancellous bone C, when damaged, has been known to have a restoration speed that is about 10 times faster than that of the cortical bone S that is characteristically relatively hard.
However, when the amount of the alveolar bone B is not sufficient at a buccal surface or a lingual surface or fenestration is performed close to the buccal surface or the lingual surface due to an error of an operator, the cortical bone S may be dehiscenced or fenestrated at one side surface or both side surfaces of the alveolar bone B as illustrated in FIGS. 3, 4, and 6.
In a case in which the implant hole H is ruptured (dehiscence) or formed (fenestration) in a side surface, when the dental implant fixture 1 is implanted as illustrated in FIG. 5, as a diameter of the dental implant fixture 1 is larger than a diameter of the implant hole H, the dental implant fixture 1 applies excessive pressure to the cortical bone S around the implant hole H. Accordingly, for a firm and stable implantation of the dental implant fixture 1, an alveolar bone ridge augmentation treatment needs to be further performed using a bone graft material 2 or a shield film 2.
To address the above problem, there is a demand for a fixture that does not apply excessive pressure to the cortical bone S of the alveolar bone B.